The Research Of The Coal Slime Water Dosing System Based On Grey Fuzzy Control

Coal slime water treatment is an important production process in coal washery. In the process of Coal slime water treatment, it realizled the flocculant automatically adds and guaranteeing washery water reuse and closed-circuit circulation, not only are related to technology and economic index of coal washery, but also to the protection of the environment. At present, many coal washeries mainly rely on the manual work to adjust flocculant dosage. It is a waste of potions, as well as can’t ensure the quality of the circulating water. Though the auto-system have been realized in part of some coal washeries, for the complexity of the coal slime settlement process, there are still flaws in the system, specially the system can not solve the problem of system lag. Therefore, it is significant for coal washery to study advanced control method and improve the control effect.This paper analyzes and researches dosing system of coal slime water and slime water settlement process. It is a complicated and multiple factors-affected delay nonlinear process, so it is hard to develop practical mathematical model. To solve this problem, this paper proposes the feedforward and feedback joint control strategy. Feedforward control, according to the material concentration, flow and potions system, assure appropriate dosage. Feedback control use grey prediction fuzzy control algorithm. By grey model, to forecast the turbidity value of system, that forecasts the turbidity value of the future time according to the present and the past turbidity and changing behavior of turbidity. Take the predicted value as input of the fuzzy controller, apply fuzzy control algorithm to timely adjust dosage correction. Such method using grey prediction eases the influence caused by system lag, and uses fuzzy control solving the problem of system model unknown.This paper expounds the grey prediction algorithm and the fuzzy control algorithm. This paper firstly establishes grey prediction model using Matllab, through the Matlab simulation,researches and analyzes model to find out how the modeling dimension,volatility of original data sequence and prediction step length affect the precision of the model in the prediction. Secondly, this paper still also detailedly introduces the design process of the fuzzy controller, and implement preliminary design of the fuzzy controller.For testing,we establish simulation model of dosing system by Simulink tool of Matlab. By comparing grey prediction fuzzy control and only fuzzy control, the simulation results show that grey forecasting fuzzy control has better system performance and better anti-interference ability.According to needs of slime water automatic dosing system, we design and implement automatic dosing control system which is composed of upper machine PC, lower machine PLC300, concentration sensor, flow sensor and turbidity sensor. With operation ability of PC, grey forecasting process is realized by Mingled-Programming between Matlab and asp.net. System Sensor data acquisition and the dosage of the fuzzy control were done by PLC. Upper machine and lower machine can exchange data and control information through the industrial Ethernet network.